1. Field of the Invention
This invention relates to location by GPS signals and more particularly to a method and a device for integration of an RF GPS emulator in a simulation environment.
2. Discussion of Related Art
The development of new vehicles, in particular aircraft, requires numerous simulations. Depending on the state of development of the vehicle and the objective sought, these simulations may be purely software, hardware or mixed, that is to say based on software and hardware components. In this way, the integration of actual components such as computers, sensors and actuators may be simulated.
Furthermore, in order to study the reactions of the vehicle or of certain of these components, it may be necessary to integrate emulators into the simulation. Emulators are used to reproduce the performance of a part of the vehicle or that of an outside element interacting with a part of the vehicle. Again, these emulators may be software, hardware or mixed.
In particular, there are emulators called GPS (abbreviation for Global Positioning System in English terminology) emulators or RF GPS (abbreviation for Radio Frequency) emulators that produce GPS signals, similar to those received from satellites, from indications of position and time. In this way, from a spatial position of latitude, longitude and altitude type and an indication of time, it is possible to reconstitute the signals that would be received by a GPS sensor located at this point at this moment. Depending on the emulators, these signals are electromagnetic waves or corresponding electrical signals.
This type of emulator is used, in particular, to test the navigation systems of aircraft, ships and automobiles.
Nonetheless, because of the precision of location calculated by GPS and the speed of the vehicles using the navigation systems, the indications of position and time generally must be extremely precise in order to validate the functioning of the simulated pieces of equipment.